Association strengthened with longer course of treatment

Action Points

Both antidepressant use and depression diagnoses were associated with increasing body mass index (BMI) in older children and teenagers.

Note that the results are very similar to findings in adults and suggest that depressed children with or without antidepressant therapy should be carefully monitored for weight gain.

NEW ORLEANS -- Both antidepressant use and depression diagnoses were associated with increasing body mass index (BMI) in older children and teenagers, researchers said here.

These associations strengthened over time, so the longer a child had been taking antidepressants or had a diagnosis of depression, the stronger the association with BMI, reported Brian Schwartz, PhD, of Johns Hopkins Bloomberg School of Public Health in Baltimore, and colleagues. The results were presented at Obesity Week 2016 and published simultaneously in the November issue of Obesity.

"We were interested in whether the healthcare system contributes to obesity, and we focused on depression because there has been an increase in the prevalence of antidepressants used by children," Lisa Bailey-Davis, DEd, RD, of Geisinger Health System in Pennsylvania, said in her presentation. "Obesity can increase the risk of developing depression, and depression can accentuate weight gain."

The research team has examined different pharmacologic exposures and their association with BMI in children for 3 years -- first looking at attention deficit hyperactivity disorder (ADHD) and stimulants in 2014, and then antibiotics in 2015 and antidepressants this year.

The strongest associations between BMI and antidepressants were found when a child had received the treatment for more than 12 months (β=0.521, SE 0.055, P<0.001). The link with BMI was even stronger when examining selective serotonin re-uptake inhibitors (SSRI) use only for the same period of time (β=0.771, SE 0.066, P<0.001).

When a child had received antidepressant treatment for more than 12 months, there was an association with a mean weight gain of 2.1 kg at age 18 compared with children who had received no antidepressants. This rose to 2.5 kg when the antidepressant was an SSRI.

This was especially significant, said Bailey-Davis, because SSRIs made up 64.1% of antidepressant orders in this population. In addition, more than a quarter of children who had been prescribed SSRIs were taking another antidepressant.

"While this weight gain is by no means trivial and it may be associated with an increased risk of metabolic disease, it is not as high as for antipsychotic drugs," he wrote. "However, overall the results are very similar to findings in adults and suggest that depressed children with or without antidepressant therapy should be carefully monitored for weight gain."

Although the study by Bailey-Davis et al concentrated on the relationship between antidepressants and BMI, with her saying that the goal was to "de-tangle depression from antidepressant use," the research also examined the relationship between depression diagnosis and BMI.

Compared with children with no depression diagnoses, those with at least one such diagnosis were associated with a higher average BMI (β=0.297, SE 0.040, P<0.001). Similar to the situation for antidepressant treatment, associations between BMI and length of depression diagnosis strengthened gradually over time (>3 years duration of diagnosis: β=0.523, SE 0.097, P<0.001).

Not surprisingly, when the relationship between BMI and antidepressants was adjusted for depression diagnosis, the associations were slightly attenuated, although there was still a link between the two (β=0.487, SE 0.077, P<0.001 for 12+ months of antidepressant use).

For the study, the team examined electronic health record data from 105,163 children ages 8 to 18, with a mean age of 12. Antidepressant use was based on prescriptions for the treatment. Overall, 5.9% of children had a diagnosis of depression and 10.1% received antidepressant treatment.

Children taking antidepressants received their first prescription order at an average age of 9, and treatment lasted an average of 9 months. Both the percentage of children with depression diagnoses and those taking antidepressants increased from 1% to 2% at age 8 to 12% to 16% at age 18. Interestingly, children who received Medical Assistance/Medicaid (which represented 30.9% of all examined BMIs) were 2.0 to 2.5 times more likely to be treated with antidepressants.

Asked for his opinion, Joseph Skelton, MD, of Wake Forest Baptist Medical Center's Center on Diabetes, Obesity, and Metabolism, noted that the study does not answer the "chicken or the egg" question in terms of whether obesity or depression comes first, but that clinicians need to have awareness to address depression before attempting to change other behaviors.

"I think you can say depression is a co-morbid condition, and you need to address that if you're hoping to improve that child's overall health, which is the goal in any case," Skelton told MedPage Today. "I think there is still a big 'chicken or the egg' point to it, but the study is great because it ties obesity and depression together much more strongly than other studies that have been done."

This study was supported by the Global Obesity Prevention Center at Johns Hopkins University and by National Institute of Health grants.

Accessibility Statement

At MedPage Today, we are committed to ensuring that individuals with disabilities can access all of the content offered by MedPage Today through our website and other properties. If you are having trouble accessing www.medpagetoday.com, MedPageToday's mobile apps, please email legal@ziffdavis.com for assistance. Please put "ADA Inquiry" in the subject line of your email.